Method of communication between devices operating within a wireless communication system

ABSTRACT

A subscriber station (SS) utilizes uplink resources that have been assigned to it for communicating with an infrastructure station to exchange data with a neighboring SS while maintaining its link to the infrastructure station. This is accomplished by the SS receiving an uplink allocation from the infrastructure station, transmitting a subscriber-to-infrastructure station header and trailer to the infrastructure station using the modulation and coding scheme (MCS) assigned by the infrastructure station and also transmitting a subscriber-to-subscriber (S2S) message payload, optionally using a second MCS level appropriate for the link between itself and the receiving SS. The subscriber to infrastructure station message is composed so that it occupies the first m codewords and contains a header that describes the length of the subscriber to infrastructure station message. The subscriber to infrastructure station message, then, is followed by the S2S message, composed to occupy the remaining symbols of the allocation.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to wireless communicationsystems and more particularly to a method of communication betweendevices operating within a wireless communication system.

BACKGROUND

Many wireless communication systems today are composed of a number offixed base stations (BS) which are distributed geographically over anetwork coverage area and are communicatively coupled together eithervia wired links or wireless links. Wireless communication devices (alsoreferred to as “subscriber stations (SSs)”, mobile devices, and thelike) within coverage of a base station can communicate via the basestation with other subscriber stations within coverage of the basestation.

Time Division Duplexing (TDD) refers to a transmission scheme thatallows an asymmetric flow for uplink and downlink transmission which ismore suited to data transmission. In a Time Division Duplex system, acommon carrier is shared between the uplink and downlink, the resourcebeing switched in time. Users are allocated one or more timeslots foruplink and downlink transmission.

Examples of TDD scheduled mobile radio systems include communicationsystems operating using Time Division Code Division Multiple Access(TD-CDMA) air interface, Time Division Synchronous Code DivisionMultiple Access (TD-SCDMA), Digital Enhanced Cordless Telecommunications(DECT), Institute of Electrical and Electronics Engineers (IEEE) 802.16Worldwide Interoperability for Microwave Access (WiMAX), and Long TermEvolution (LTE).

For example, Institute of Electrical and Electronics Engineers (IEEE)802.16 is a point-to-multipoint (PMP) system with one hop links betweena base station (BS) and a subscriber station (SS). Any of the IEEEstandards or specifications referred to herein may be obtained athttp://standards.ieee.org/getieee802/index.html or by contacting theIEEE at IEEE, 445 Hoes Lane, PO Box 1331, Piscataway, N.J. 08855-1331,USA. The Institute of Electrical and Electronics Engineers (IEEE) 802.16Working Group on Broadband Wireless Access Standards is a unit of theIEEE 802 LAN/MAN Standards Committee that aims to prepare formalspecifications to support the development and deployment of broadbandWireless Metropolitan Area Networks.

LTE (Long Term Evolution) refers to a new air interface that is beingdeveloped by 3GPP in its Release 8 Specification set. Any of the 3GPPstandards or specifications referred to herein may be obtained athttp://www.3gpp.org/specifications.

LTE will provide users with an experience similar to that of fixed linebroadband both in terms of bandwidth and latency, meaning applicationsthat can be delivered today on fixed line will soon be available overthe air and fully mobility with LTE.

Time Division Duplexing (TDD) systems such as IEEE 802.16 and similarmobile/base style systems, such as LTE, provide no method oftransmitting data directly between subscriber stations (SS). Instead,all data transferred from one SS to another must be sent through thebase station (BS). A more efficient method of transferring data is tosend it directly from one SS to another. However, as the standards donot currently support this functionality, a method of providing thefunctionality without modifying the standards is desired.

Accordingly, there is a need for a method and apparatus for enhancedsubscriber-to-subscriber communication within a wireless communicationsystem.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying figures, where like reference numerals refer toidentical or functionally similar elements throughout the separateviews, together with the detailed description below, are incorporated inand form part of the specification, and serve to further illustrateembodiments of concepts that include the claimed invention, and explainvarious principles and advantages of those embodiments.

FIG. 1 illustrates a wireless communication network for use in theimplementation of at least some embodiments.

FIG. 2 illustrates an infrastructure station for use in the wirelesscommunication network of FIG. 1 in accordance with at least someembodiments.

FIG. 3 is an electronic block diagram of a subscriber station for use inthe wireless communication network of FIG. 1 in accordance with at leastsome embodiments.

FIG. 4 illustrates a transmission structure for communication within thewireless communication network of FIG. 1 in accordance with at leastsome embodiments.

FIG. 5 illustrates an alternative transmission structure forcommunication within the wireless communication network of FIG. 1 inaccordance with at least some embodiments.

FIG. 6 illustrates an operation of a transmitting subscriber stationwhen composing a data transmission in accordance with some embodiments.

FIG. 7 illustrates the operation of FIG. 6 in terms of the variouscomponents of the data transmission in accordance with some embodiments.

FIG. 8 illustrates an example network implementing the operation of atleast some of the various embodiments.

FIG. 9 illustrates a data transmission resulting from the example ofFIG. 8 in accordance with some embodiments.

Skilled artisans will appreciate that elements in the figures areillustrated for simplicity and clarity and have not necessarily beendrawn to scale. For example, the dimensions of some of the elements inthe figures may be exaggerated relative to other elements to help toimprove understanding of embodiments of the present invention.

The apparatus and method components have been represented whereappropriate by conventional symbols in the drawings, showing only thosespecific details that are pertinent to understanding the embodiments ofthe present invention so as not to obscure the disclosure with detailsthat will be readily apparent to those of ordinary skill in the arthaving the benefit of the description herein.

DETAILED DESCRIPTION

A method is provided herein whereby a subscriber station (SS) may useuplink resources that have been assigned to it for communicating with aninfrastructure station such as a base station (BS) or a relay station(RS) to exchange data with a neighboring SS while maintaining its linkto the infrastructure station. It does this by receiving an uplinkallocation, for example, from a base station, transmitting asubscriber-to-infrastructure station header and trailer to theinfrastructure station using the modulation and coding scheme (MCS)assigned by the infrastructure station and also transmitting asubscriber-to-subscriber (S2S) message payload, optionally using asecond MCS level appropriate for the link between itself and thereceiving SS. The subscriber station to infrastructure station messageis composed so that it occupies the first m codewords and contains aheader that describes the length of the subscriber station toinfrastructure station message. The subscriber station to infrastructurestation message, then, is followed by the S2S message, composed tooccupy the remaining symbols of the allocation. This second part ishidden behind the portion that the infrastructure station will attemptto process, so the infrastructure station is effectively unaware of itscontents. The CRC or similar error detection mechanism is calculatedbased on how data transmitted at a first MCS would be interpreted by astation receiving that data and expecting a second MCS. This approachdoes not require any changes to infrastructure station equipment and canbe implemented completely in subscriber devices. This approach allows asingle transmission to be received and meaningfully interpreted bymultiple stations. It allows existing systems to be retrofitted withdirect link capabilities without requiring an upgrade to the existinginfrastructure.

FIG. 1 illustrates a wireless communication network for use in theimplementation of at least some embodiments. FIG. 1 illustrates aparticular non-limiting example of one network configuration,specifically an IEEE 802.16 network 100. As illustrated, the network 100includes at least one base station 105 for communication with aplurality of subscriber stations 110-n (also known as mobile stations).It will be appreciated that although only one base station isillustrated in FIG. 1 for simplicity purposes, any number of basestations can be included within the network 100. The network 100 furtherincludes a plurality of relays 115-n (also known as relay stations orrepeaters). The relays 115-n are deployed in the areas with poorcoverage and relay transmissions so that subscriber stations 110-n in acell boundary can connect using high data rate links. In some casesrelays 115-n may also serve subscriber stations 110-n that are out ofthe coverage range of the base station 105. In some networks, the relays115-n are simpler versions of the base station 105, in that they do notmanage connections, but only assist in relaying data. Alternatively, therelays 115-n can be at least as complex as the base station 105.Further, all or some of the relay stations 115 can be deployed in amulti-hop pattern. In other words, some relays such as 115-6 communicatewith the base station 105 via other relays such as 115-5. Further, theserelays can be within each other's coverage. RS5 115-5 is considered tobe an ascendant station (i.e., a station through which RS6 115-6communicates with the BS) for RS6 115-6 and RS6 115-6 is considered tobe a descendant station for RS5 115-5.

FIG. 2 illustrates an infrastructure station such as a base station 105or a relay station 115 of FIG. 1 in accordance with at least someembodiments. As illustrated, the infrastructure station comprises aplurality of ports 200-n, a controller 205, and a memory 210.

Each port 200-n provides an endpoint or “channel” for networkcommunications by the infrastructure station. Each port 200-n may bedesignated for use as, for example, an IEEE 802.16 port or a backhaulport. For example, the infrastructure station can communicate with oneor more other base stations and/or relay stations and/or one or moresubscriber stations within an 802.16 network using an IEEE 802.16 port.An IEEE 802.16 port, for example, can be used to transmit and receiveboth data and management information.

A backhaul port similarly can provide an endpoint or channel forbackhaul communications by the infrastructure station. For example, theinfrastructure station can communicate with one or more otherinfrastructure stations using the backhaul, which can be wired orwireless, via the backhaul port.

Each of the ports 200-n are coupled to the controller 205 for operationof the infrastructure station. Each of the ports employs conventionaldemodulation and modulation techniques for receiving and transmittingcommunication signals respectively, such as packetized signals, to andfrom the infrastructure station under the control of the controller 205.The packetized data signals can include, for example, voice, data ormultimedia information, and packetized control signals, including nodeupdate information.

The controller 205 includes a scheduler 230 for the management of bothuplink and downlink communication with the various subscriber stations(SS) 110-n and relay stations (RS) 115-n associated with theinfrastructure station. It will be appreciated by those of ordinaryskill in the art that the scheduler 230 can be hard coded or programmedinto the infrastructure station during manufacturing, can be programmedover-the-air upon customer subscription, or can be a downloadableapplication. It will be appreciated that other programming methods canbe utilized for programming the scheduler 230 into the infrastructurestation. It will be further appreciated by one of ordinary skill in theart that the scheduler 230 can be hardware circuitry within theinfrastructure station. In accordance with the present invention, thescheduler 230 can be contained within the controller 205 as illustrated,or alternatively can be an individual block operatively coupled to thecontroller 205 (not shown).

To perform the necessary functions of the infrastructure station, thecontroller 205 is coupled to the memory 210, which preferably includes arandom access memory (RAM), a read-only memory (ROM), an electricallyerasable programmable read-only memory (EEPROM), and flash memory.

It will be appreciated by those of ordinary skill in the art that thememory 210 can be integrated within the infrastructure station, oralternatively, can be at least partially contained within an externalmemory such as a memory storage device. The memory storage device, forexample, can be a subscriber identification module (SIM) card.

FIG. 3 is an electronic block diagram of a subscriber station 110 inaccordance with at least some embodiments. The terminology “subscriberstation” and “mobile station” are used interchangeably herein to referto subscribers who may be fixed, nomadic or mobile. As illustrated, thesubscriber station 110 includes an antenna 300, a transceiver (or modem)305, a processor 310, and a memory 315.

The antenna 300 intercepts transmitted signals from one or more basestations 105, one or more relay stations 115, and/or one or moresubscriber stations 110 within the network 100 and transmits signals tothe one or more base stations 105, one or more relay stations 115,and/or one or more subscriber stations 110 within the network 100. Theantenna 300 is coupled to the transceiver 305, which employsconventional demodulation techniques for receiving and transmittingcommunication signals, such as packetized signals, to and from thesubscriber station 110 under the control of the processor 310. Thepacketized data signals can include, for example, voice, data ormultimedia information, and packetized control signals, including nodeupdate information. When the transceiver 405 receives a command from theprocessor 310, the transceiver 305 sends a signal via the antenna 300 toone or more devices within the network 100. For example, the subscriberstation 110 can communicate with one or more base stations and/or one ormore relay stations and/or one or more subscriber stations within an802.16 network by the antenna 300 and the transceiver 305 using IEEE802.16, for example, to transmit and receive both data and managementinformation.

In an alternative embodiment (not shown), the subscriber station 110includes a receive antenna and a receiver for receiving signals from thenetwork 100 and a transmit antenna and a transmitter for transmittingsignals to the network 100. It will be appreciated by one of ordinaryskill in the art that other similar electronic block diagrams of thesame or alternate type can be utilized for the subscriber station 110.

Coupled to the transceiver 305, is the processor 310 utilizingconventional signal-processing techniques for processing receivedmessages. It will be appreciated by one of ordinary skill in the artthat additional processors can be utilized as required to handle theprocessing requirements of the processor 310.

To perform the necessary functions of the subscriber station 110, theprocessor 310 is coupled to the memory 315, which preferably includes arandom access memory (RAM), a read-only memory (ROM), an electricallyerasable programmable read-only memory (EEPROM), and flash memory. Itwill be appreciated by those of ordinary skill in the art that thememory 315 can be integrated within the subscriber station 110, oralternatively, can be at least partially contained within an externalmemory such as a memory storage device. The memory storage device, forexample, can be a subscriber identification module (SIM) card.

In most (time division duplex) TDD scheduled mobile radio systems, suchas LTE and 802.16, subscriber stations (SS) request uplink resourcesfrom an infrastructure station such as a relay station (RS) or a basestation (BS). The infrastructure station allocates uplink resources andassigns a Modulation and Coding Scheme (MCS) to those resources.Subscriber stations may use the assigned resources only for transmittingdata directly to the infrastructure station.

It will be appreciated by those skilled in the art that although theremaining embodiments are described in terms of a transmittingsubscriber station communicatively coupled to a base station and anothersubscriber station coupled to the same base station, alternativeembodiments of implementation within the scope of the invention include,and are not limited to a subscriber station and a relay station, andalso the two subscriber stations can be connected to the same ordifferent base stations or the same or different relay stations or anycombination, thereof.

FIG. 4 illustrates one embodiment of a transmission structure in whichthe resources are used to transmit data directly to a neighboring SS byencoding a portion of the transmission at the MCS instructed andexpected by a BS and optionally a second portion of the data at a secondMCS receivable by a neighboring SS. This can be done even in the casewhere the base station is not expecting a subscriber to subscriberexchange. By carefully structuring the transmission, the portion of thedata intended for the neighboring SS will be located such that the BS isnot aware that the subscriber to subscriber data is being transmitted.

As illustrated in FIG. 4, codewords [1, m] 400 are transmitted at thesubscriber station to base station MCS and codewords [m+1, n] 405 aretransmitted at the subscriber station to subscriber MCS. Codewords [1,m] 400 include a Media Access Control (MAC) header (SB_(Hb)) 420, uplink(UL) data (UL_(b)) 425, a cyclic redundancy check (CRC) (SB_(Tb)) 430, asubscriber to subscriber header (SS_(Hb)) 435, and a portion(SS_(SB-Hb)) 440 of an embedded subscriber to subscriber packet payload.Codewords [m+1, n] 405 include a second portion (SS_(SS) _(—) _(b)) 445of the embedded subscriber to subscriber packet payload.

The subscriber station to base station payload (SB_(b)) 410 includes theMedia Access Control (MAC) header (SB_(Hb)) 420, the uplink (UL) data(UL_(b)) 425, and the cyclic redundancy check (CRC) (SB_(Tb)) 430. Thesubscriber station to subscriber station payload (SS_(b)) 415 includesthe subscriber to subscriber header (SS_(Hb)) 435 and both the portion(SS_(SB-Hb)) 440 and the second portion (SS_(SS) _(—) _(b)) 445 of theembedded subscriber to subscriber packet payload.

FIG. 5 illustrates an alternative embodiment of a transmission structurein which the resources are used to transmit data directly to aneighboring SS. In this embodiment, the subscriber to subscriber portionof the transmission begins in the first codeword after the subscriberstation to base station portion of the transmission (i.e. codeword m+1).Whatever parts of the first m codewords that are not filled by uplinkdata messages are filled with pad bits.

As illustrated in FIG. 5, codewords [1, m] 500 are transmitted at thesubscriber station to base station MCS and codewords [m+1, n] 505 aretransmitted at the subscriber station to subscriber MCS. Codewords [1,m] 500 include a Media Access Control (MAC) header (SB_(Hb)) 520, uplink(UL) data (UL_(b)) 525, a subscriber to subscriber header (SS_(Hb)) 530,a cyclic redundancy check (CRC) (SB_(Tb)) 535, and a pad 540. Codewords[m+1, n] 505 include the embedded subscriber to subscriber packetpayload 545.

The subscriber station to base station payload (SB_(b)) 510 includes theMedia Access Control (MAC) header (SB_(Hb)) 535, the uplink (UL) data(UL_(b)) 525, the subscriber to subscriber header (SS_(Hb)) 530, and thecyclic redundancy check (CRC) (SB_(Tb)) 535. The subscriber station tosubscriber station payload (SS_(b)) 515 includes just the embeddedsubscriber to subscriber packet payload 545.

Although it will be appreciated that either embodiment can beimplemented, subsequent discussions hereinafter will revolve around themethod described previously and illustrated in FIG. 1.

An SS wishing to transmit data directly to another SS using resourcesallocated for an SS-to-BS (S2B) link encodes and modulates the first mcodewords of its transmission using an MCS (SB_(MCS)) dictated by the BS(see FIG. 4). The SB_(MCS) is composed of a rate (SB_(rate)) andmodulation (SB_(mod)). The first m codewords are comprised of at leastany messages expected by the BS including optional uplink data messages.Some of the first m codewords may optionally contain a headerinstructing the receiving SS how to decode the transmission in order torecover the S2S payload portion. The m^(th) codeword may also include aportion of the S2S payload as necessary to fill the codeword.

The remaining portion of the transmission, the portion beginning afterthe m^(th) and up to and including the n^(th) codeword, are encoded andmodulated either at the MCS (SB_(MCS)) dictated by the BS, or optionallyat an MCS (SS_(MCS)) achievable between the pair of SSs and ideallyoptimized for the number of symbols available in this region. The codingrate and modulation chosen for this link are labeled SS_(rate) andSS_(mod). The S2S data transmitted at the SS_(MCS) is comprised of anypayload portion of the transmitted message that was not contained in anyof the first m codewords.

In order to prevent the BS from attempting to process the transmitteddata that exists after the S2B message, the transmitting SS composes thesize, length or similar field of the S2B header to indicate that the S2Bdata is the extent of the message. For example, if the total of all theuplink data messages were 100 bytes followed by 1500 bytes of S2S data,then the length field of the S2B header should be set equal to 100 bytesassuming that the header describes the total transmission length. Thisshould prevent the BS from attempting to process anything beyond thefirst 100 bytes of the transmission.

The transmitting subscriber station also composes error detection orcorrection mechanisms, such as a cyclic redundancy check (CRC),checksum, parity bit array, etc, accordingly. That is, the mechanismonly covers the S2B portion of the transmitted message (i.e. the firstSB_(Hb)+UL_(b) bits) and should not cover the S2S portion, though asecond error detection or correction mechanism may be included to coverthat part.

The parameters required to receive the S2S portion of the transmissioncould be known by the receiving SS a priori, calculated from the knowntransmission parameters or included in the transmission. If the receiveparameters are not known a priori and cannot be calculated, then theymust be communicated to the receiving SS in some way. One way to do thisis to place a header containing receive parameters somewhere in thefirst m codewords, which are sent using the SB_(MCS). The receiving SSwould demodulate and decode codewords at the SB_(MCS) until the headeris found, at which point the station would learn the location of the S2Spayload transmitted using the SSMCS. The S2S header could be placedafter all of the S2B data, as shown in FIG. 4, or could be placed insideof the uplink data, as shown in FIG. 5. The receiving SS could learn theSB_(MCS) by receiving broadcast resource assignments, such as the 802.16UL-MAP. Alternately, the S2S header could be included at a fixed rateand placed at a known symbol offset into the allocation. In either case,the S2S header could be used to transport fields such as the SS_(MCS)used, the number of SS_(MCS) symbols, the number of S2S payload bits,etc. There are likely other methods, such as using predefined fixed S2Sparameters, to achieve a similar effect.

The embedded S2S payload is encoded at the SS_(MCS). The BS willdemodulate and decode the entire received transmission using SB_(MCS).Provided there are favorable channel conditions, the first m codewords,which contains the MAC header, any uplink traffic, and potentially anS2S header and a portion of the S2S payload, will be demodulated anddecoded without error by the BS. Because the length, size or similarfield of the transmitted MAC header describes the message as beingcontained only within the first m codewords, the BS ignores all datathat occurs after the indicated number of bytes. As a result, the errordetection or correction mechanism should operate without fault eventhough an incorrect MCS was used to decode the transmission of codewords[m+1, n]

FIG. 6 illustrates an operation 600 of a transmitting subscriber stationwhen composing its transmission to a BS and a neighboring SS inaccordance with some embodiments. FIG. 7 illustrates the operation ofFIG. 6 in terms of the various components of the data transmission 700in accordance with some embodiments.

The operation 600, as illustrated, begins with Step 605 in which thetransmitting SS determines the length of the header (705), uplinkmessages (710), subscriber-to-subscriber (S2S) payload (715) and trailer(It will be appreciated by those of ordinary skill in the art that thetrailer is the CRC for the first m codewords). The calculations oftransmit durations in symbols and bits will be discussed hereinafterwith regards to Tables 1 through 3.

Next, in Step 610, the transmitting subscriber station composes the S2Smessage to be transmitted such that it occupies SS_(b) bits includingall embedded headers, where SS_(b) represents the number of unused bitsfrom the first m codewords and the number of unused bits from the lastn−m+1 codewords. The S2S payload is segmented or aggregated as necessaryand pad bits are added as needed.

Next, in Step 615, the transmitting subscriber station encodes (encoder732) the header (705), uplink data messages (710), S2S header (712) andfirst SS_(SB) _(—) _(Hb) bits (718) of the S2S payload using theSB_(MCS).

Next, in Step 620, the transmitting subscriber station encodes (encoder725) SS_(SS) _(—) _(b) S2S payload bits (720) in the range (SS_(SB) _(—)_(Hb), SS_(b)) at the SS_(rate) generating codewords [m+1, n].

Next, in Step 625, the transmitting subscriber station modulates(modulator 735) codewords [1, m] (the subscriber-to-base header (705),uplink messages (710), S2S header (712) and first bits of the S2Spayload (718)) (head bits 730) using SB_(mod) generating pad symbols asnecessary and stores all produced symbols (symbols 740).

Next, in Step 630, the transmitting subscriber station modulates(modulator 745) codewords [m+1, n] (the S2S payload (715)) (center bits720) using SS_(mod) generating pad symbols as necessary and store allthe produced symbols (symbols 740). Alternatively, a rate matchingmechanism could be used to fill all available symbols in codewords [m+1,n].

Next, in Step 635, the transmitting subscriber station concatenates thesymbols and transmits.

The BS will demodulate and decode the transmission using SB_(MCS).Because the BS is using SB_(MCS) to receive the transmission, the datain the SS_(MCS) section will be received differently than it wastransmitted. However, because the S2B MAC header indicates that themessage only occupies the first SB_(b) bits of the transmission, no partof the incorrectly demodulated and decoded transmission is processed bythe BS.

Calculations of Transmit Durations in Symbols and Bits

The following calculations assume that no rate matching or codepuncturing is being employed in order to match the number of bits codedat the SB_(MCS) to the number of available symbols. Instead, it isassumed that code words are designed to produce a number of symbolsevenly divisible by the associated modulation.

Before the constant and variable definitions are provided, anexplanation must be given as to what is considered a symbol. A symbol istraditionally a time unit only. However, Orthogonal Frequency-DivisionMultiple Access (OFDMA) provides the ability to transfer multiplemodulated constellations within a single symbol time; e.g. eachsubcarrier is modulated independently and can thus carry a differentmeaning during each symbol time.

TABLE 1 List of constants and their definitions Value Definition SNumber of data symbols in the allocation SB_(rate) Coding rate fromsubscriber to base (S2B) SB_(mod) Number of modulated bits per symbolachievable on the S2B link SS_(rate) Coding rate from subscriber tosubscriber (S2S) SS_(mod) Number of modulated bits per symbol achievableon the S2S link SB_(Hb) Header size (in bits) required in S2B messageSB_(Tb) Trailer size (in bits) required in S2B message UL_(b) Number ofuplink message bits SS_(Hb) Number of bits in S2S header SB_(CW) _(—)_(length) Length, in symbols, of a codeword using SB_(rate) and SB_(mod)

TABLE 2 Station-to-base variables, their equations and definitionsVariable Equation Definition SB_(b) SB_(Hb) + UL_(b) + SB_(Tb) Totalnumber of bits in the S2B part of the transmission. SB_(Hs)$\frac{{S\; B_{Hb}} + {U\; L_{b}} + {S\; B_{Tb}} + {S\; S_{Hb}}}{S\; B_{rate} \times S\; B_{mod}}$Number of symbols, whole and fractional, required to send the compositeheader containing the required S2B header, uplink message bits and S2Sheader CW_(whole)$\left\lfloor \frac{S}{S\; B_{CW\_ length}} \right\rfloor$ Number ofwhole codewords that fit in an allocation of S symbols CW_(H)$\left\lceil \frac{S\; B_{Hs}}{S\; B_{CW\_ length}} \right\rceil$ Numberof codewords required to transmit SB_(Hs) symbols SB_(H—unused)$\quad\left( \begin{matrix}{{C\; W_{H} \times S\; B_{CW\_ length}} - {S\; B_{Hs}}} & , & {{C\; W_{H}} \leq {C\; W_{whole}}} \\{S - {S\; B_{Hs}}} & , & {{C\; W_{H}} > {C\; W_{whole}}}\end{matrix} \right.$ Number of symbols from the S2B header codewordsthat are not used by the header/uplink messages

TABLE 3 Station-to-station variables, their equations and definitionsSS_(S) S − (SB_(Hs) + SB_(H) _(—) _(unused)) Number of symbols availablefor transmission at the SS_(MCS) SS_(SB) _(—) _(Hb) SB_(H) _(—)_(unused) × SB_(rate) × SB_(mod) Number of bits available in the unusedpart of the S2B leading codewords transmitted at the SB_(MCS) SS_(SS)_(—) _(b) └SS_(S) × SS_(rate) × SS_(mod)┘ Total number of whole bitsavailable to the S2S payload in the SS_(MCS) transmission part. Hereagain a floor function is required because a fractional number of bitscan be generated from certain numbers of input symbols. It is assumedthat extraneous symbols are pad symbols, that rate matching is employedor that the coder is somehow designed to avoid this issue. SS_(b)SS_(SB) _(—) _(Hb) + SS_(SS) _(—) _(b) Total number of whole bitsavailable for the S2S payload from all parts of the transmission

FIG. 8 illustrates an example of a portion of a wireless communicationnetwork 800 for implementing at least some of the various embodimentsdiscussed previously herein. As illustrated in FIG. 8, the SS pair (SS1805 and SS2 810) are geographically located close together, while boththe SSs (SS1 805 and SS2 810) are geographically remote from the BS 815.In this case, it is possible that the BS 815 would grant a 912 symboluplink allocation from SS 1 805 using an MCS of QPSK ½ and an associatedcodeword length of 128 bits or 128 symbols. In this case, also considerthat the link between SS 1 805 and SS 2 810 can sustain an MCS of 64QAM½.

FIG. 9 illustrates a data transmission 900 for consideration along withthe example of FIG. 8. As illustrated, the example data transmission 900includes an 8 byte (64 bits) S2B MAC header 905; a 16 bytes (128 bits)of uplink messages 910, a 32 bit CRC 915 and a 1 byte S2S header 920.

The SS would need to send the S2B MAC header 905, the uplink messages910, the CRC 915 and the S2S header 920 all at the SB_(MCS), a total of64+128+32+8=224 bits. This means that the first two codewords, or first256 symbols, need to be transmitted at the SB_(MCS), though only thefirst 224 symbols are needed, which leaves 32 symbols for use intransporting S2S data at the SB_(MCS) rate. This also leaves 912−256=656symbols available for transmission at the SS_(MCS). Transmitting 656symbols at the SS_(MCS) provides an additional 1968 bits to the S2Spart. This results in a total of 1968+32=2000 bits available fortransporting data between the S2S pair.

Contrast this with sending all data to the BS at the SB_(MCS). As in theprevious example, the transmission must include the S2B MAC header 905,the uplink messages 910, and a CRC 915. It will not, though, require thetransmission of an S2S header 920. Transporting all data at theSB_(MCS), then, would provide 896−64−128−32=672 bits of payload. The S2Slink provides nearly three times the capacity of the S2B link.

A novel method of using an uplink transmit resource for sending datadirectly to a peer device has been provided herein. This approach doesnot require any changes to base station equipment and can be implementedcompletely in subscriber devices. It allows existing systems to beretrofitted with direct link capabilities without requiring an upgradeto the existing infrastructure. This idea could be used in any systemwith multi-codeword uplink transmissions where station-to-station linksare desired. A good example of such a system is 802.16e.

In the foregoing specification, specific embodiments have beendescribed. However, one of ordinary skill in the art appreciates thatvarious modifications and changes can be made without departing from thescope of the invention as set forth in the claims below. Accordingly,the specification and figures are to be regarded in an illustrativerather than a restrictive sense, and all such modifications are intendedto be included within the scope of present teachings.

The benefits, advantages, solutions to problems, and any element(s) thatmay cause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeatures or elements of any or all the claims. The invention is definedsolely by the appended claims including any amendments made during thependency of this application and all equivalents of those claims asissued.

Moreover in this document, relational terms such as first and second,top and bottom, and the like may be used solely to distinguish oneentity or action from another entity or action without necessarilyrequiring or implying any actual such relationship or order between suchentities or actions. The terms “comprises,” “comprising,” “has”,“having,” “includes”, “including,” “contains”, “containing” or any othervariation thereof, are intended to cover a non-exclusive inclusion, suchthat a process, method, article, or apparatus that comprises, has,includes, contains a list of elements does not include only thoseelements but may include other elements not expressly listed or inherentto such process, method, article, or apparatus. An element proceeded by“comprises . . . a”, “has . . . a”, “includes . . . a”, “contains . . .a” does not, without more constraints, preclude the existence ofadditional identical elements in the process, method, article, orapparatus that comprises, has, includes, contains the element. The terms“a” and “an” are defined as one or more unless explicitly statedotherwise herein. The terms “substantially”, “essentially”,“approximately”, “about” or any other version thereof, are defined asbeing close to as understood by one of ordinary skill in the art, and inone non-limiting embodiment the term is defined to be within 10%, inanother embodiment within 5%, in another embodiment within 1% and inanother embodiment within 0.5%. The term “coupled” as used herein isdefined as connected, although not necessarily directly and notnecessarily mechanically. A device or structure that is “configured” ina certain way is configured in at least that way, but may also beconfigured in ways that are not listed.

It will be appreciated that some embodiments may be comprised of one ormore generic or specialized processors (or “processing devices”) such asmicroprocessors, digital signal processors, customized processors andfield programmable gate arrays (FPGAs) and unique stored programinstructions (including both software and firmware) that control the oneor more processors to implement, in conjunction with certainnon-processor circuits, some, most, or all of the functions of themethod and/or apparatus described herein. Alternatively, some or allfunctions could be implemented by a state machine that has no storedprogram instructions, or in one or more application specific integratedcircuits (ASICs), in which each function or some combinations of certainof the functions are implemented as custom logic. Of course, acombination of the two approaches could be used.

Moreover, an embodiment can be implemented as a computer-readablestorage medium having computer readable code stored thereon forprogramming a computer (e.g., comprising a processor) to perform amethod as described and claimed herein. Examples of suchcomputer-readable storage mediums include, but are not limited to, ahard disk, a CD-ROM, an optical storage device, a magnetic storagedevice, a ROM (Read Only Memory), a PROM (Programmable Read OnlyMemory), an EPROM (Erasable Programmable Read Only Memory), an EEPROM(Electrically Erasable Programmable Read Only Memory) and a Flashmemory. Further, it is expected that one of ordinary skill,notwithstanding possibly significant effort and many design choicesmotivated by, for example, available time, current technology, andeconomic considerations, when guided by the concepts and principlesdisclosed herein will be readily capable of generating such softwareinstructions and programs and ICs with minimal experimentation.

The Abstract of the Disclosure is provided to allow the reader toquickly ascertain the nature of the technical disclosure. It issubmitted with the understanding that it will not be used to interpretor limit the scope or meaning of the claims. In addition, in theforegoing Detailed Description, it can be seen that various features aregrouped together in various embodiments for the purpose of streamliningthe disclosure. This method of disclosure is not to be interpreted asreflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter lies in less than allfeatures of a single disclosed embodiment. Thus the following claims arehereby incorporated into the Detailed Description, with each claimstanding on its own as a separately claimed subject matter.

We claim:
 1. A method of communication between communication devicesoperating within a wireless communication system, the method comprising:a subscriber station requesting, from an infrastructure station, uplinkresources assigned by the infrastructure station for communicating withthe infrastructure station; the subscriber station composing atransmission burst for transmission using the assigned uplink resources,wherein the transmission burst comprises (i) a first portion including asubscriber-to-infrastructure station header field and composed fordemodulation and decoding by the infrastructure station and at least oneneighboring subscriber station, and (ii) a second portion including anembedded subscriber-to-subscriber packet composed for demodulation anddecoding by the at least one neighboring subscriber station;transmitting, using the assigned uplink resources, the transmissionburst from the subscriber station to the at least one neighboringsubscriber station and to the infrastructure station; the infrastructurestation receiving the transmission burst; and the infrastructure stationdemodulating and decoding the first portion and ignoring the secondportion of the transmission burst.
 2. A method as claimed in claim 1,further comprising: the neighboring subscriber station receiving thetransmission burst; and the neighboring subscriber station demodulatingand decoding the first portion and the second portion of thetransmission burst.
 3. A method as claimed in claim 1, wherein the atleast one infrastructure station comprises one or more of a base stationand a relay station.
 4. A method as claimed in claim 1, wherein thesubscriber station and the at least one neighboring subscriber stationare communicatively coupled to the infrastructure station.
 5. A methodas claimed in claim 1, wherein the subscriber station and the at leastone neighboring subscriber station are communicatively coupled todifferent infrastructure stations.
 6. A method as claimed in claim 1,wherein the composing of the transmission burst comprises: encoding thefirst portion of the transmission burst using a first modulation andcoding scheme; and encoding the second portion of the transmission burstusing a second modulation and coding scheme different from the first. 7.A method as claimed in claim 6, further comprising: receiving thetransmission burst by the at least one infrastructure station;demodulating and decoding the first portion and the second portion ofthe transmission burst by the at least one infrastructure station usingthe first modulation and coding scheme; and not processing the secondportion of the transmission burst by the at least one infrastructurestation.
 8. A method as claimed in claim 7, further comprising:receiving the transmission burst by the at least one neighboringsubscriber station; demodulating and decoding the first portion of thetransmission burst by the at least one neighboring subscriber stationusing the first modulation and coding scheme; and demodulating anddecoding the second portion of the transmission burst by the at leastone neighboring subscriber station using the second modulation andcoding scheme; and processing the second portion of the transmissionburst by the at least one subscriber station.
 9. A method as claimed inclaim 8, further comprising processing at least part of the firstportion of the transmission burst by the at least one subscriber stationto obtain information on how to demodulate and decode the second portionof the transmission burst.
 10. A method as claimed in claim 6, furthercomprising the subscriber station selecting the first modulation andcoding scheme to meet a channel quality between the subscriber stationand the at least one infrastructure station.
 11. A method as claimed inclaim 6, further comprising the subscriber station selecting the secondmodulation and coding scheme to meet a channel quality between thesubscriber station and the at least one neighboring subscriber station.12. A method as claimed in claim 1, wherein the first portion of thetransmission burst further comprises a trailer comprising a cyclicredundancy check of the first portion of the transmission burst.
 13. Amethod as claimed in claim 1, wherein the first portion of thetransmission burst occupies a first m codewords and wherein the secondportion of the transmission burst occupies a set of remaining symbols ofa transmission burst allocation.
 14. A method as claimed in claim 13,wherein the first portion of the transmission burst further comprises anuplink data and a cyclic redundancy check, and wherein the secondportion of the transmission burst further comprises a subscriber tosubscriber header.
 15. A method as claimed in claim 14, wherein thesubscriber-to-infrastructure station header field describes thetransmission burst as containing only the first m codewords, therebycausing the infrastructure station to ignore the second portion of thetransmission burst.
 16. A method as claimed in claim 1, wherein thesecond portion of the transmission burst begins at a first codeword(m+1) after a first m codewords in the first portion, and furtherwherein a remaining portion of the first m codewords that are not filledby one or more uplink data messages are filled with one or more padbits.
 17. A method as claimed in claim 16, wherein the first portion ofthe transmission burst further comprises an uplink data, a subscriber tosubscriber header, and a cyclic redundancy check.